Diaphragm for sound boxes



J. E. ROBINS AND W. S. SLACK;

DIAPHRAGM FOR SOUND BOXES.

APPLICATION FILED 02s. 1920.

1 ,41 9 ,943. Patented June 20, 1922.

UNITED STATES PATENT OFFICE.

nuns nnwnm norms AND-WILLIAM srALLwoon sum, or naennsvmm, ONTARIO, CANADA.

Specification of Letters Patent.

Patented .June 20, 1922.

Application filed December 1, 1920. Serial No. 427,514.

T 0 all whom it may concern:

Be it known that we, JAMES EDWARD ROBINS and WILLIAM STALLWOOD SLACK, of the town of Hagersville, in the county of Haldimand and Province of Ontario, Dominion of Canada, have invented certain new and useful Improvements in Diaphragms for Sound Boxes; and we hereby declare that the following is a full, clear, and exact description of the same.

This invention relates todiaphragms for phonographs, made from the untanned dressed abdominal Walls of bovidae, technically known by the English term abdominal tunic and the Latin term tunica. flava abdominis, the object of the invention being to so prepare the material for these discs that they will correctly reproduce the sounds with the same tonal effect as the original sounds.

Heretofore in the reproduction of sounds by phonographs and the like, the tonal effects of the instruments have been marred by the inability of the diaphragms, owing to the material from which they have been made, to accurately reproduce the correct pitch and exact number of vibrations of the original sounds.

The object of the present invention is to overcome these defects, this object being attained as hereinafter set forth and particularly pointed out in the claims.

In the drawings:

Fig. 1, is a plan view, and

Fig. 2, is a side elevation of a diaphragm made in accordance with this invention.

In carrying out the invention the abdominal tunic, i. e., the tunica flava abdominis of a bovine, is thoroughly cleaned of all fatty substances and flesh and then stretched and dried, by any usual or approved method suitable for this purpose.

. This untanned dressed material is then ground to a proper thickness, preferabl by means of fine sand paper or emery cloth,

and rendered proof against climatic changes by a coat of commercial gold size japan dr er rubbed in by hand.

hen this material is properly prepared each diaphragm disc will respond uniformly to all vibrations of the stylus, and equally distribute the sound waves over its entire surface, thereby producing the natural tones of the original sounds with a resonance which 18 not only mellow and voluminous, but also entirely free from those impairments common to metallic and wooden diaphragms.

While we prefer to use the abdominal walls of bovidae, we wish it to be understood that we do not desire the invention confined to membranous material taken from these animals, nor do we Wish to be confined to the use of gold size japan dryer as the sizing composition.

Having thus fully described my invention, What I claim as new and desire to secure by Letters Patent is:

. 1. A diaphragm forsound reproducing instruments composed of the abdominal tunic of a bovine.

2. A diaphragm for sound reproducing instruments composed of the untanned dressed h abdominal tunic of a bovine.

3; A diaphragm for sound reproducing instruments composed of the abdominal tunic of a bovine which has been cleaned of fatty substances and flesh and then stretched and dried.

4:. A diaphragm for sound re roducing instruments composed of the ab ominal tunic of a bovine from which has been removed all fatty substances and flesh and which has been thoroughly stretched, dried and ground to the desired thickness.

Toronto, Ontario, November 20th, 1920.

JAMES EDWARD ROBINS. WILLIAM STALLWOOD SLACK.

Signed in the presence of-- DANIEL CARTER, CHAS. H. RIoHEs. 

